1. Field
The present disclosure relates to an interconnecting-type solid oxide fuel cell, and more particularly, to an interconnecting-type solid oxide fuel cell having an efficient current collecting structure and a fuel cell stack having the same.
2. Description of the Related Technology
Fuel cells may be classified according to type of electrolyte. Since the fuel cells have various power ranges, usages and the like, a suitable fuel cell can be selected according to its intended purpose. In solid oxide fuel cells, it is relatively easy to control the position of an electrolyte, and there is limited risk of exhausting the electrolyte because of its fixed position. Further, since the solid oxide fuel cells resist corrosion, solid oxide fuel cells have a relatively longer lifetime. For these reasons, the solid oxide fuel cells have come into the spotlight as fuel cells widely used in commerce and domestic use.
Meanwhile, the voltage of a unit cell used in a solid oxide fuel cell may not be as high as compared with that required in a practical use. Therefore, to obtain a required voltage, the rated voltage and capacity of the fuel cell may be designed by electrically connecting a plurality of unit cells in series or in parallel.
When a conventional stack is manufactured using anode-supported tubular-type unit cells, current collection is performed using Ni foam, and the unit cells are electrically connected to one another. However, since gas supplied to the stack should pass through a porous medium, fuel cannot be efficiently supplied to the stack when the unit cells have a relatively longer length. Since the current collection is performed using the porous Ni foam, a current collector does not contact with the unit cell surface, but may merely contact the cell via an electrical wire. Accordingly, the current collection efficiency of the current collector is decreased. Therefore, the performance of the stack may be degraded due to a failure in the supply of gas and/or an increase in current collecting resistance.